Normal intervertebral discs between endplates of adjacent vertebrae distribute forces between the vertebrae and cushion vertebral bodies. The spinal discs may be displaced or damaged due to trauma, disease or aging. A herniated or ruptured annulus fibrosis may result in nerve damage, pain, numbness, muscle weakness, and even paralysis. Furthermore, as a result of the normal aging processes, discs dehydrate and harden, thereby reducing the disc space height and producing instability of the spine and decreased mobility. Most surgical corrections of a disc space include a discectomy, which can be followed by restoration of normal disc space height and bony fusion of the adjacent vertebrae to maintain the disc space height.
Access to a damaged disc space may be accomplished from several approaches to the spine. One approach is to gain access to the anterior portion of the spine through a patient's abdomen. However, extensive vessel retraction is often required and many vertebral levels are not readily accessible from this approach. A posterior approach may also be utilized. This approach typically requires that both sides of the disc space on either side of the spinal cord be surgically exposed, which may require a substantial incision or multiple access locations, as well as extensive retraction of the spinal cord. To alleviate problems associated with both anterior and posterior approaches to the spine, a postero-lateral approach to the disc space may be utilized.
There remains a need for improved instruments, implants and techniques for use in a postero-lateral approach to a spinal disc space that facilitate disc space preparation and implant insertion to provide bilateral stability to the subject disc space.